Two or more sensors are often used to detect different or even the same parameters. In one non-limiting example, a Forward Based X-Rand Radar subsystem may be used in a missile defense application to detect, track, and discriminate threats. Other radar subsystems such as a Sea-Based X-Band Radar may also be used in the missile defense application.
When a threat is launched, the missile and its warheads and decoys are tracked. A battle management center then receives the output from the various radar subsystems and deploys, sometimes automatically, an interceptor to destroy any threats. The radar subsystems output kinematic data (e.g., the number of detected objects, their location, speed, and trajectory) as well as classification data with assigned probabilities.
The classification data may discriminate, as between numerous detected objects, whether they are lethal or not, friend or foe, and their type (e.g., re-entry vehicle, decoy, and the like), among other classification criteria.
Each radar subsystem includes a unique database and software which outputs class probability vectors which are a function of the measurements obtained from the radar itself and the database of that radar subsystem. As between a Forward Based X-Band Radar subsystem and a Sea-Based X-Band Radar subsystem, for example, the respective measurements may be different for a given target. The respective radar databases may also be configured differently. And, the software based analysis carried out by each subsystem to analyze their measurements as a function of their respective databases may be different. This is especially true for radar subsystems supplied by different vendors and/or at different times or as between different versions in a product development effort.
So, one radar subsystem may provide, to the battle management center, a sensor class probability vector P1 as a function of its measurements Y1 and its database D1 and a different radar subsystem may provide a different sensor class probability vector P2 as a function of its measurements Y2 and its database D2.
It would be advantageous, then, to configure the different radar subsystems to transmit their actual measurements to the battle management center and classify potential threats based on all the incoming measurements. Currently, because of the configuration of the various radar subsystems, this is not possible. Also, the data communications interfaces would have to change.
Multiplying and normalizing the probability vectors from each radar subsystem does not work because correlations are ignored. Other possible solutions either fail to yield accurate results or are difficult to implement.